Chromotography of polyolefin polymers
AssigneeDow Global Technologies LLC
InventorsFreddy Van Damme, John W. Lyons, William L. Winniford, Alexander W. Degroot, Matthew D. Miller
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Abstract
A method and apparatus for chromatography of a polyolefin polymer by flowing a solution of the polyolefin polymer through liquid flowing through a graphitic carbon liquid chromatography stationary phase. The method can be used to determine the monomer to comonomer ratio of a polyolefin copolymer such as a copolymer of ethylene and 1-octene or a copolymer of propylene and ethylene.
Claims6
A method for determining the monomer to comonomer ratio of a copolymer consisting essentially of ethylene and an alpha olefin comonomer, comprising the steps of:
- (a) flowing a liquid mobile phase into contact with a liquid chromatography stationary phase comprising graphitic carbon to produce an effluent stream of liquid mobile phase from the stationary phase;
- (b) introducing a solution of the copolymer into the liquid mobile phase so that the copolymer emerges in the effluent stream with a retention factor that varies as a mathematical function of the monomer to comonomer ratio of the copolymer.
A method for determining the monomer to comonomer ratio of a copolymer consisting essentially of propylene and an alpha olefin comonomer, comprising the steps of:
- (a) flowing a liquid mobile phase into contact with a liquid chromatography stationary phase comprising graphitic carbon to produce an effluent stream of liquid mobile phase from the stationary phase;
- (b) introducing a solution of the copolymer into the liquid mobile phase so that the copolymer emerges in the effluent stream with a retention factor that varies as a mathematical function of the monomer to comonomer ratio of the copolymer.
Dependencies are inferred from the claim text.